Speed regulator



May 21, 1935. J. LARSON EF'AL 2,002Q150 I SPEED REGU TOR Filed Dec. 9 932 M'ER J, ARSON IN NTO ATT NEY Patented May 21, 1935 j i 1 UNITED sTATEs PATENT OFFICE SPEED REGULATOR Iner J. Larson, Oaklyn, and John J. Hoehn, Camden, N. J., assignorsto Radio Corporation of America, a corporation of Delaware Application December 9, 1932, Serial No. 646,512

\ 3 Claims. (o1. 188-187) This invention relates to speed regulators, and and 6 against which the tongue of the member 3 more particularly to speed regulators adjustable strikes to stop it in predetermined positions.

to one or the other of two positions, such as are The adjusting knob is provided with a spindle used. on phonographs or spring-driven motion H! which passes through an appropriate aperture p fl e Cameras. 7 in the frame member 18, and at the end of this 5 In such devices it has heretofore been customspindle is a reduced portion ll having a screw ary to provide an indicator plate or stop-plate thread. This screw thread fits into a COIIG:

on the camera case, and in order that the proper sponding thread in the member l2, so that rotaspeeds might be secured it was necessary that tion of the knob i, causing rotation of the portion 10 either the indicator or stop-plate be adjustable, H, causes a movementof the member I2 axially. 10 or that there be an adjustment between the conof the screw. The member [2 'is prevented from trol knob and the governor itself. "Both of these, rotating by a slot i3 therein which slides longiarrangements were undesirable, as they are liketudinally upon the pin l4. ly to get out of adjustment, were difiicult to A rather stifi spring I 5 surrounds the spindle adjust, and were expensive. I llland bears against the frame member l8 and 15 In our invention, an adjustable stop member the member I2 and thereby maintains the adis fixed to the control knob and is arranged to be justing knob I firmly in contact with the stop locked thereto in adjusted position, and the dismember 3, and causes this stop member to bear advantages hereinbeiore stated are i thereby firmly against the washer I on the frame member avoided. l8thereby accurately defining the position of 2 One objectof our invention is to provide an the member l2. improved speed regulator which can be easily Inserted into the member I2 is the usual fibreshifted from one of two predetermined speeds plug or the like l6 which is adapted to cooperate to another. with the plate I I of the governor when the speed Another object of our invention is to provide of the device becomes too great and to provide 25 an improved speed regulator which is inexpena braking effectthereupon, thereby maintaining Sive to manufacture and assemble but which is the speed at the proper point. nevertheless accurate. It will be apparent that rotationof the knob l Another object of our invention is to provide from the point where the member abuts against such a device having a positive stop at each of the stop 6 to the point where the member 3 abuts 30 two predetermined positions. I against the stop 5 will cause a certain change Another object of our invention is to provid in the speed of theapparatus, and the range of such a device having a stop member which is this speed variation can be accurately predeterreadily adjustable. mined by the pitch of the screw II, the stiffness In the drawing; of the springs of the governor and the weight of 35 Figure 1 is a front view of the control-knob the fly-balls of the governor. On the other hand and stop-plate. h the exact points at which these stops would func- Figure 2 is a side view, partly in section, of tion cannot readily and accurately be predeterour adjusting device as applied to the governor mined on account of the necessary manufacturof a camera or phonograph. ing tolerances in, for example, the thickness of 40 Figure 3 is an exploded view showing the relathe plate II, the point circumferential of the I tion of the adjustable stop to the control knob. member H at which the screw thread starts, the

The control knob, indicated at I, preferably length of the shoulder I0, the thicknesses of the lies with, its face slightly below the face of the members 3 and 1, etc. It is therefore necessary camera-case (or other casing of the apparatus) that arelative adjustment be provided between 45 2, and is made in the form of an ordinary screwthe adjustable stop member 3 and the brake head with the slot therein of sufficient size so that member l6 so that when the member 3 is against the knob may be actuated by the insertion of either the shoulder 5 or the shoulder 6 the apthe edge of a coin or the like. paratus will operate at the desired speed.

The adjustable stop-plate, indicated generally It will be seen from Fig. 3 that the back of the 50 at 3, is loosely mounted on the spindle I 0 and knob I is provided with a plurality of radial lies against the back of the head i, and the progrooves 8, while the member 3 is provided with jecting tongue thereof extends upwardly past the four radial ridges indicated at 9 of such shape head i into the annular recess 4. i as to cooperate with the grooves 8. When the g This recess 4 is provided with two shoulders 5 device is assembled in the relation shown in 55 Fi 2. at least one pair of these radial ridges on the member 3 will fit into the radial grooves in the member I and'will be maintained firmly therein by the action of the spring l5. to accomplish the adjustment hereinbeiore mentioned, the knob I is rotated until the member 3 is against either the shoulder 5 or the shoulder 6 depending on which speed is to be measured, and the speed of the apparatus is then measured or otherwise checked against the standard. It will be apparent that if the thread on the member I I is a right-hand thread, then rotation of the knob I in a clockwise direction will decrease the speed, and rotation of the knob i in a counter-clockwise direction will increase the speed, wherefore the stop indicator 5 will indicate a high speed and the stop indicator 6 will indicate a lower speed. If with the member 3 against the stop 5 the speed is not sufficiently high, the knob I is forced to rotate still further in the counterclockwise direction until the speed reaches the proper amount. This rotation can be forced without damaging the member 3 since, on the application of sufiieient pressure, the spring It: will yield and the corrugations 8 will ride over the ridges 9 until such excess pressure is discontinued when these parts will be retained against further relative movement by the action of the spring I5. If in the position 5 the speed of the device is too high, the knob is rotated until the member 3 strikes the stop 5 and is then further rotated by an appropriate amount, whereupon it can again be rotated until the member 3 strikes the stop 5 to check the speed at this point. If the speed is measured at the position 8, the reverse procedure would be used.

Thisinvention is particularly useful in connection with motion picture cameras of the amateur or 16 mm. type since in such cameras it is sometimes desirable to take silent pictures which normally operate at sixteen frames per In order second, while when it is desired to take sound films it is necessary that the film be operated at the standard speed of twenty-four frames per second. In this instance, the device would be so constructed that at the position 5 the camera would run at twenty-four frames per second, at position 6 it would run at sixteen frames per second. When applied to such a camera the member 2 would ordinarily be the side of the camera case.

It will be apparent that our invention can be applied to any analogous apparatus intended to operate at two different predetermined speeds.

Having thus described our invention;

We claim:

1. Adjusting means for speed control apparatus comprising an adjusting knob, a spindle mounted upon said adjusting knob, a stop member loosely mounted upon said spindle and rotatable therewith, the adjacent faces of said knob and stop member having inter-engaging teeth and means for yieldably retaining said teeth in engagement.

2. Means for stopping the rotation of a'member rotatable through a portion only of a revolution at a predetermined point comprising a fixed stop upon a stationary member adjacent said rotatable member, and a stop member adapted to cooperate with said fixed stop and rotatable With the said member, and means for maintaining said movable stop rigidly in predetermined relation to said rotatable member under normal operating pressures but yieldable under excessive pressures.

3. In combination, a rotatable control knob, an index member, inter-engaging teeth upon said control knob and said index member, and spring means maintaining said teeth in engagement whereby said knob and said index member are normally rotatable as a unit but are relatively adjustable.

INER J. LARSON. JOHN J. HOEI-IN. 

